COMEDK2014MathematicsPermutation and Combination
If a polygon of n sides 275 diagonals, then n is equal to
Options
- A25
- B35
- C20
- D15
Correct answer
A. 25
Step-by-step solution
A polygon of n sides has number of diagonals = n(n-3) 2 =275 [given] n²-3 n-550=0 (n-25)(n+22)=0 n=25 [n -22]